procedure for the production of precipitated calcium carbonate with high opacity by reacting sodium carbonate with calcium hydroxide

摘要

In the process for making calcium carbonate by the double decomposition reaction of sodium carbonate and calcium hydroxide in aqueous reaction medium the improvement of producing calcium carbonate having a scalenohedral particle shape and a rosette aggregate structure comprising adding said sodium carbonate in more than one stream to said calcium hydroxide over a period of 1 to 8 hours and maintaining said reaction medium in the range of 80 DEG to 140 DEG F.